Six exposures from the Hubble Space Telescope were combined to create this mosaic of comet P/Shoemaker-Levy 9 on May 17, 1994. When the comet was observed, its train of 21 icy fragments stretched across 710 thousand miles (1.1 million km) of space, or 3 times the distance between Earth and the Moon. Credit: H.A. Weaver, T. E. Smith (STScI), NASA
